Circular knitting machines



Nov. 19, 1968 A. w. KENT ET AL I 3,411,326

' CIRCULAR KNITTING MACHINES Filed Sept. 1, 1964 6 Sheets-Sheet 1 Nov. 19, 1968 A.-w KENT ET AL 3,411,326

CIRCULAR KNITT ING MACHINES Filed Sept. 1, 1964 6 Sheets-Sheet 2 Nov. 19, 1968 A. w. KENT ET AL I 3,411,326

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CIRCULAR KNITTING MACHINES Filed Sept. 1, 1964 6 Sheets-Sheet 5 Nov. 19, 1968 A. w. KENT ET AL 3,411,326

CIRCULAR KNITTING MACHINES Filed Sept. 1, 1964 6 Sheets-Sheet 6 HG. I3

United States Patent 3,411,326 CIRCULAR KNITTING MACHINES Alfred Woodward Kent, Rothley, and Gillies Wood,

Leicester, England, assignors to The Bentley Engineering Company Limited, Leicester, England Filed Sept. 1, 1964, Ser- No. 393,542 Claims priority, application Great Britain, Sept. 5, 1963, 35,143/63 11 Claims. (Cl. 6654) ABSTRACT OF THE DISCLOSURE A needle cam arrangement whereby during the splicing operation those selected needles utilized therefore descend the stitch to its lowest point. The butts of the needles at said point engage a small pivotal cam, which is interconnected to the stitch cam, thereupon privoting said small cam and adjusting the stitch cam and thus forming longer loop length during the splicing operation.

This invention is for improvements in or relating to circular knitting machines and has for an object to provide a convenient and effective means whereby the stitch size may be varied to suit requirements in certain parts of tubular knitted fabric such as blanks which are used in the manufacture of articles of hosiery.

In the manufacture of seamless stockings such as are made wholly by rotary knitting to form tubular blanks which are subsequently shaped on a board or formed to produce a pouch area by distortion of the fabric structure, such pouched area is often reinforced with a splicing yarn. To facilitate shaping of the spliced area into pouch form it is found to be advisable to increase the stitch length in the spliced area so as to provide some fullness of fabric to assist the pouch formation. The invention seeks to provide means whereby such fullness may be formed in the spliced pouch area in a convenient and effective manner.

Insertion of a splicing yarn to form the spliced area to provide a heel pouch requires the splicing yarn to be knitted only part of the Way round the blank and to different extents. This can be accomplished in known manner by one of two alternative types of splicing mechanism. One is known as the beating finger splicing in which a splicing yarn feeder is brought into activity and withdrawn from activity at appropriate times to feed yarn to the needles forming the area of fabric where the heel pouch is to be formed. The other type of splicing mechanism employs needle selection so as to cause needles required to take the splicing yarn to be raised a little above the others and the needle selection is varied as required to provide for the appropriate area of splicing to be knitted. The invention is concerned with a machine incorporating needle selection splicing mechanism.

In accordance with the invention there is provided in a circular knitting machine provided with needle selection splicing mechanism having instruments in the cylinder tricks to move selected needles suitably to take a splicing yarn, means whereby the instruments of needles so selected to take the splicing yarn are caused to vary the position of a stitch cam in such manner as to cause the selected needles to perform a longer loop drawing movement. Thus it can be provided that the extra loop length is caused to occur only in the knitting of the fabric of the spliced area. Problems of timing of the stitch cam movement can be completely avoided by arranging that the instruments of the needles selected for splicing cause adjustment of the stitch cam to take place just as their needles are approaching the bottom of the stitch cam. When the last of the group of needles selected for splic- 3,411,326 Patented Nov. 19, 1968 ing passes the bottom of the stitch cam its instrument will at the same time release the stitch cam for return to its normal setting.

The invention is particularly suitable for application to a machine having a plurality of feeding stations, for example a two or four feed machine, as it is only necessary at each feeding station to arrange for the stitch cam to be movable and controlled in the manner just referred to.

Conveniently the adjustment of the stitch cam by the instruments of needles selected for splicing is effected by butts on such instruments engaging and displacing a movable member coupled suitably to the stitch cam so that displacement of the movable member by said butts causes the required adjustment of the stitch cam. With this arrangement the butts of those instruments associated with needles selected for splicing are caused by the selection to follow a cam track different from the track followed by butts of instruments associated with needles not so selected. The instruments concerned may be intermediate jacks fitted in the cylinder tricks between the needle stems or sliders and selecting instruments used for pattern selection. When splicing is required say at an area to form a heel pouch the appropriate selecting instruments raise their associated intermediate jacks to cause their butts to follow a higher than normal cam track. The jacks are then raised to such a height as to cause their needles to take the splicing thread, whilst the other needles do not take such threads. After the jacks of the selected needles have so raised their needles they are lowered to permit the needles to descend the stitch cam, and just as the jacks approach their lowest position their butts encounter a movable member in the form of a small cam which is connected to the stitch cam. The butts of the jacks so lowered are caused to lower the small cam and in so doing adjust the stitch cam.

By means of the mechanism just described the slackened area can be made to conform exactly with the spliced area without any special timing or any additional selecting mechanism. In the case of fine gauge machines such as are used for knitting ladies stockings the jacks and other knitting elements are of thin construction without great strength. Since the stitch cam only needs to be lowered a very short distance to increase the loop length which distance may be about one hundreth of an inch, it is dvantageous to arrange that the movable member operated by the butts of the instruments to adjust the stitch cam is caused to be lowered by substantially greater distance than the stitch cam, and to have movement reducing mechanism coupling said movable member to the stitch cam. The movement reduction mechanism may have a ratio of about ten to one so that the movable member will move approximately ten times as far as the stitch cam so reducing considerably the stress on the butts of the instruments.

In practising the invention with a machine having a plurality of feeding stations there may be a fresh selection of needles for splicing at each feeding station or knitting location, or one selection can be maintained over two or more feeding stations with appropriate slackening arrangements at each.

If it is not desired to splice the area to form a heel portion, the fabric may still be slackened by the means provided by the invention, by using the appropriate selection of needles, but not feeding any splicing yard to them.

A convenient embodiment of the invention as applied to a multi-feed circular knitting machine for the manufacture of ladies stockings, will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a development view seen from the inside of a part of the cam system in the cam box,

FIGURE 2 is an elevation view showing the parts used for adjusting the stitch cam,

FIGURE 3 is an end elevation view partly in cross section as seen from the right of FIGURE 2 of certain of the same parts,

FIGURE 4 is a diagrammatic view showing the relative portions of selecting jacks and needles for needles which do not take the splicing thread,

FIGURE 5 is a view similar to FIGURE 4 but for needles selected to take the splicing thread,

FIGURES 6 to 9, show diagrammatically in different positions of a modified arrangement for controlling the stitch cam,

FIGURE 10 is a schematic view, similar to FIG. 1, but showing the complete cam development of the cam system.

FIG. 11 is a fragmentary sectional view, taken on the line XX of FIG. 2,

FIG. 12 is a fragmentary sectional view, similar to FIG. 3 but taken on the line YY of FIG. 2, and

FIG. 13 is a fragmentary sectional view of the mechanism of FIGS. 6-9.

The machine illustrated as an example is of the rotating cylinder type, having a long cylinder containing needles 2, intermediate jacks 3 and 3a, and selecting jacks 4. Any type of selecting means may be used, and jacks 4 in this example are caused either to miss the raising cam 5 or to travel upwards upon it. Those that travel upwards raise their intermediate jacks 3a, FIG- URE 1, so that they go over cam 6, while the others 3, maintain their low position and go below cam 6.

The jacks 3a that rise up earn 6 ultimately lift up their needles 2. Normally the needles approach the knitting location 7 in a cleared position (that is, with the latches of the needles raised above the stitches) as shown in FIGURE 4. They are then high enough all to take the ground yarn 9 at the knitting location 7, from the feeder 10, but below feeder 13. Needles above the selected raised jacks 3a, however, are lifted higher, at position 11, than the others, so that they can take splicing yard 12 from feeder 13 which is placed early in the feed throat 8, and higher than feeder 11 see FIGURE 5. After passing feeder 13 the raised needles are lowered to join the others and they take the ground yarn 9 also and descend stitch cam 14 to knit. Meanwhile the raised intermediate jacks 3a have been lowered by cam 15, and as they reach a point almost below the point of the stitch cam 14, they encounter a small cam 16.

The cam 16 is connected by levers (as will be described later) with stitch cam 14 and, in order to pass, the intermediate jacks must lower this cam 16 as they are lowered fully by cam 15. Then by the lever connections, the stitch cam 14 is also lowered, but due to the leverage provided, only through a much shorter, but adequate, distance. This causes longer loops to be drawn by the needles above the selected intermediate jacks, and cam 16 is maintained in its lowered position, and the stitch cam with it, while the batch of selected jacks goes by. As soon as the last of these jacks has passed, the stitch cam is returned to its higher position by a spring 17. Thus the stitch cam is lowered exactly in conformity with the needles which take the splicing yard, with no additional selecting devices.

Referring now to FIGURES 1 and 2, the stitch cam 14 is fixed to block 18, together with its guard cam 32 and this block is slidable vertically on cam box 19 and re tained by cover plate 20. It is urged upwards by spring 17 against stop 21. This is set for normal knitting. The general stitch length adjustment is carried out in normal manner by raising and lowering the cylinder as is well known.

In multi-feed machines the stitch cams 14, 14a, etc. must all be set to knit equal loops, by adjusting stops 21, for normal operation, so that uniform fabric can be produced. Then each stitch can be slackened for the spliced portion as it goes through the various knitting positions 4 in turn. Attached to the slidable block 18 is pin 22 and fulcrumed upon this is lever 23. Its short end contact the underside either of pin 24 or of slide 25 and will be described later. The longer end of lever 23 is slotted to receive link 26 which has an adjustable nut 27 at its upper end. The lower end is bent at right angles and passes freely into a hole in lever 28. This lever is fulcrumed on pin 29 in block 30 attached to the underside of the cambox 19, and on the end of this lever 28 is attached the small cam 16.

The action is as follows. Downward movement of cam 16 causes (as viewed in FIGURE 2) clockwise movement of lever 28 and through the link 26 downward movement of the calibrated nut 27. This causes lever 23 to pivot in an anticlockwise direction about the pin22 with a resulting upward movement of the short end of the lever 23 causing it to press on the underside of slide 25. However, because slide 25 is mounted on the rod 24 which is secured to the cambox, it will resist this upward movement of lever 23 and cause the pin 22 in the slide block 18, on which the lever 23 is mounted. to be depressed thus lowering cam 14.

Thus movement of cam 16 tends to move the stitch cam 14 in the same direction but to a much less degree due to the leverage of the movement. The adjustment of nut 27 is such however that if the slide 25 is held clear of lever 23 the small cam 16 can move downwards sufficiently to allow the butts of the intermediate jacks 3a to pass without affecting the stitch cam 14.

If however the slide 25 is moved so as to be interposed between the pin 24 and lever 23 as shown in FIGURE 3, then when the selected intermediate jacks encounter cam 16 they will operate to lower the stitch cam 14, the amount of its movement being determined by the adjustment of the nut 27 The slide 25 is thus the control member for the slackening device, and can be moved into and out of action by a Bowden wire from the normal control drum and a spring 31, in well known manner, and can so determine whether selected intermediate jacks can be caused to slacken the fabric or not, and at any required feed. This is desirable because the jacks may be used for selection for other purposes than for splicing.

In the example shown, a selection for knitting location 7 is repeated at knitting location 33 and an appropriate cam 15a, with corresponding lever mechanisms as before will cause stitch cam 14a to be lowered as the intermediate jacks pass by, thus one feed only may be so operated, or any desired number of feeds.

If the invention is applied to a machine which produces the normal reciprocated heel and/ or toe, when a separate yarn is used for these portions, it may be used to slacken a spliced portion such as the foot bottom, and to be held out of action for other parts of the stocking.

An additional feature may be incorporated, shown in FIGURES 6 to 9. It may be desired to confine the slackened portion well within the spliced area, so that there is no danger of the un-spliced stitches being slackened. To achieve this the small cam 16 may be made wider, with a raised portion at each end as shown at 16a, and fulcrumed at 16b, so that it can rock. Above is cam 15 which terminates in a substantially horizontal portion 15b, above cam 16a. The arrangement is such that as the first selected intermediate jacks encounter the first raised portion of cam 16a, they will twist it slightly in a clockwise direction as in FIGURE 7, so that its top edge slopes and not until sufiicient jacks have gone below the horizontal edge 15b, to engage with both ends of cam 16a (see FIGURE 8) will the cam 16a be fully lowered and the stitch cam with it, so that the very first needles to take splicing will not have their stitches slackened.

Similarly, at the termination of the slackened portion, as soon as the last jack passes the first raised part of cam 16a, the cam 16 will twist in an anti-clockwise direction as in FIGURE 9 and the slackening will terminate even though the last jacks have not fully passed it.

What we claim is 1. In a circular knitting machine having needle selection splicing mechanism including instruments in needle cylinder tricks to move selected needles suitably to take a splicing yarn, the combination comprising a stitch cam, means mounting said stitch cam for movement to vary the loop drawing stroke of needles, instruments for controlling the movement of the needles, and means whereby the movement of the instruments associated with needles selected for movement to the splicing position causes the position of the stitch cam to be varied to cause the needles associated with such instruments to perform a longer loop drawing movement.

2. In a circular knitting machine provided with needle selection splicing mechanism, the combination with the knitting machine needles of instruments associated respectively with said needles, selection means whereby the instruments of predetermined needles are moved to cause their needles to be deflected from a normal path into a position to receive a splicing yarn, cam means acting on said needles and said instruments to operate them and including a stitch cam, means mounting the stitch cam for movement to vary the loop drawing movement of the needles, and means whereby the instruments of needles predetermined for movement to splicing position are caused by their movement to effect adjustment of the stitch cam to cause the related needles to perform a longer than normal loop drawing movement.

3. A combination according to claim 2 wherein the means causing the instruments to efiect adjustment of the stitch cam causes such adjustment to take place as the related needles are approaching engagement with the bottom of the stitch cam.

4. A combination according to claim 2 wherein the means for effecting adjustment of the stitch cam comprises butts on the instruments, a movable member actuated by the instrument butts, and means coupling said movable member to the stitch cam.

5. A combination according to claim 4 comprising means whereby the butts of instruments associated with needles predetermined for movement into position to receive a splicing yarn, are caused by the action of the selection means to follow a track different from the track followed by butts of other instruments. 7

6. A combination according to claim 2 wherein the said instruments are constituted by intermediate jacks and selecting instruments are provided associated respectively with the needles and used for selecting needles to be moved into position to receive a splicing yarn, said selecing instruments being arranged to act on the jacks which are interposed between the selecting instruments and the needles.

7. A combination according to claim 2 comprising a small cam connected to a stitch cam, butts on the instruments, and means mounting said small cam in a position to engage butts of instruments which have been raised to raise their needles to the height to receive the splicing yarn and subsequently lowered during the stitch drawing movement, the engagement of the butts with said small cam occurring towards the end of the stitch drawing movement.

8. A combination according to claim 7 wherein the said small cam co-operatin g with the instrument butts is pivoted torock about an axis extending transversely of the path of the butts and has butt engaging portions extending on opposite sides of said pivot whereby engagement of the said small cam by a small group of instrument butts is necessary to effect displacement of the stitch cam from its normal setting.

9. In a circular knitting machine provided with needle selection splicing mechanism, the combination with the knitting machine needles of instruments associated respectively with said needles, selection means whereby the instruments of predetermined needles are moved to cause their needles to be raised into a position to receive a splicing yarn, cam means for operating said needles and said instruments and including a stitch cam, means mounting the stitch cam for movement to vary the loop drawing movement of the needles, butts on said instruments, a small cam engageable by the butts of instruments which have been raised to raise their needles to a position to receive a splicing yarn and have been subsequently lowered, mounting means for said small cam to permit it to be raised and lowered and coupling means including movement reducing mechanism connecting said small cam to said stitch cam.

10. A combination according to claim 9 wherein the movement reducing mechanism has a ratio of approximately 10 to 1.

11. A combination according to claim 2 applied to a machine having a plurality of feeding stations and having associated with each feeding station a stitch cam and means mounting it to permit heightwise adjustment of the stitch cam, and means whereby each of said stitch cams is adjusted in turn to vary the loop drawing movement of the needles at the related feeding station by movement of the instruments of needles selected to be moved into a position suitable for receiving a splicing yarn.

References Cited UNITED STATES PATENTS 2,200,207 5/1940 Page et al. 6654 2,983,126 5/1961 Wainwright 66-54 3,143,869 8/1966 Smith 66--48 FOREIGN PATENTS 370,868 3/ 1923 Germany. 585,894 2/1947 Great Britain.

MERVIN STEIN, Primary Examiner.

R. FELDBAUM, Assistant Examiner. 

